| 摘要 |
An extension arm 23 for a multiple hole drilling device 1, the drilling device 1 comprising a frame 17 having a first surface 19 for abutting a workpiece and drive means 3,9,11 for plunging a row of rotating drill bits 7,13 through the first surface 19 into the workpiece, the extension arm 23 comprising a body 25, adapted for attachment to the frame 17 of the drilling device 1, defining a slit 27 colinear with the row of drill bits 7,13, and a protrusion 33,31,35 accommodated within the slit 27 for engaging a drill hole formed in a workpiece, wherein the protrusion 33,31,35 is lockable to the body 25 of the extension arm 23 such that additional drill holes can be formed in the workpiece at repeatable distances along the workpiece. By enabling controlled positioning of groups of drill holes to be achieved, dowel joints requiring corresponding drill holes in two workpieces can be simply, easily and accurately produced. |
